Compositions and methods of delivering bleaching agents to teeth

ABSTRACT

The present invention relates to compositions and methods of whitening teeth of a subject in need thereof, by applying a safe and effective amount of a composition to a plurality of teeth, the composition comprising: a. a safe and effective amount of a bleaching agent; b. a safe and effective amount of a water insoluble solid phase; c. a safe and effective amount of a water soluble liquid phase; wherein the ratio of the water insoluble solid phase to the water soluble liquid phase is from about 1:4 to about 4:1; wherein the composition is applied for a sufficient period of time to achieve whitening; and wherein in one embodiment the composition has a Whitening Index of from about 0.5 to about 4. The composition optionally comprises a hydrophobically modified polymer. The present invention also relates to a delivery system comprising the present compositions used with an integral carrier, e.g. a strip material, dental tray or sponge material.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.60/530,387 filed Dec. 17, 2003, and U.S. Provisional Application No.60/530,217 filed Dec. 17, 2003, and U.S. Provisional 60/530,397, filedDec. 17, 2003.

TECHNICAL FIELD

The present invention relates to whitening compositions and to a methodof whitening teeth in a subject in need thereof. This invention alsorelates to a method of increasing efficacy of a bleaching agent in theoral cavity. The subject applies a composition to a plurality of teethfor a sufficient period of time to achieve whitening. The compositioncomprises a bleaching agent; a water insoluble solid phase; and a watersoluble liquid phase; wherein the ratio of the water insoluble solidphase to the water soluble liquid phase is from about 1:4 to about 4:1.In one embodiment the composition has a Whitening Index of from about0.5 to about 4.

In one embodiment the invention relates to a delivery system comprisingthe present compositions and an integral carrier, e.g. a strip ofmaterial, a dental tray, and/or a sponge material.

BACKGROUND OF THE INVENTION

Dental products by which various cosmetic and/or therapeutic actives aredelivered to teeth and the oral cavity are known. Examples of suchproducts include: brushing aids such as dentifrice products for deliveryof oral care actives such as polyphosphates or fluorides; mouthwashescontaining breath fresheners or antibacterial actives; and whiteningstrips for the delivery of bleaching actives to the teeth. In particularthe use of a dental strip has been recognized as a convenient andinexpensive way to deliver cosmetic and therapeutic benefits to theteeth and mucosal surfaces of the oral cavity. For example, dentalwhitening strips, where a whitening composition is applied to a stripand thereafter applied to the teeth to achieve sustained contact betweenthe teeth and the whitening composition, are known. See U.S. Pat. Nos.6,136,297; 6,096,328; 5,894,017; 5,891,453; and 5,879,691, all to Sagel,et al., and U.S. Pat. Nos. 5,989,569 and 6,045,811 both to Dirksing, etal., all assigned to The Procter & Gamble Company.

The prior art has generally attempted to increase whitening efficacy by,among other things, increasing the level of the bleaching agent in thecompositions. This approach, however, presents several problems. Firstthe subject may experience increased irritation and/or sensitivity whichmay be associated with using an increased amount of a bleaching agent.Furthermore, some regulatory authorities and legislation in variousgeographies throughout the world do not allow bleaching agents to beused in products at levels above certain concentrations.

Therefore, despite the above known approaches for the treatment of oralconditions, especially for the whitening of teeth, a need still existsfor providing products with improved bleaching efficacy. The presentinvention overcomes some of the limitations of the prior art.

SUMMARY OF THE INVENTION

The present invention relates to a method of whitening teeth of asubject in need thereof, by applying a safe and effective amount of acomposition to a plurality of teeth, the composition comprising:

-   -   a. a safe and effective amount of a bleaching agent;    -   b. a safe and effective amount of a water insoluble solid phase;    -   c. a safe and effective amount of a water soluble liquid phase;        wherein the ratio of the water insoluble solid phase to the        water soluble liquid phase is from about 1:4 to about 4:1;        wherein the composition is applied for a sufficient period of        time to achieve whitening; and wherein the composition has a        Whitening Index of from about 0.5 to about 4. In another        embodiment the composition is single phase.

In one embodiment the present invention also relates to an oral carecomposition comprising:

-   -   a. a safe and effective amount of a bleaching agent;    -   b. a safe and effective amount of a water insoluble solid phase        selected from the group consisting of organic additives and        mixtures thereof;    -   c. a safe and effective amount of a water soluble liquid phase;        and wherein the ratio of the water insoluble solid phase to the        water soluble liquid phase is from about 1:4 to about 4:1.

In another embodiment the present invention relates to an oral carecomposition comprising:

-   -   a. a safe and effective amount of a bleaching agent;    -   b. a safe and effective amount of a water insoluble solid phase;    -   c. a safe and effective amount of a water soluble liquid phase;        and    -   d. a safe and effective amount of associative thickener;        wherein the ratio of the water insoluble solid phase to the        water soluble liquid phase is from about 1:4 to about 4:1.

In another embodiment the present invention also relates to an oral caredelivery system comprising:

-   -   a. an integral carrier; and    -   b. a safe and effective amount of a composition comprising:        -   1. a safe and effective amount of a bleaching agent;        -   2. a safe and effective amount of a water insoluble solid            phase; and        -   3. a safe and effective amount of a water soluble liquid            phase;            wherein the ratio of the water insoluble solid phase to the            water soluble liquid phase is from about 1:4 to about 4:1;            and wherein the composition is applied for a sufficient            period of time to achieve whitening; and wherein the            delivery system is capable of adhesion to hard or soft            tissue of the oral cavity.

In one embodiment the delivery system comprises: a first layer of astrip material; a second layer comprising the above composition, wherebythe bleaching agent is releaseably associated to the strip material. Inone embodiment the present invention is used to deliver whiteningbenefits to the oral cavity by directly applying the integral carrier tothe teeth.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims that particularly pointout and distinctly claim the present invention, it is believed that thepresent invention will be understood better from the followingdescription of embodiments, taken in conjunction with the accompanyingdrawings, in which like reference numerals identify identical elements.The integral carrier includes a strip of material, dental tray, spongematerial, and mixtures thereof. In one embodiment of the presentinvention, the integral carrier comprises a strip of material. The stripof material is attached to the teeth via an attachment means. Theattachment means may be the present composition, an adhesive compositionseparate from the present composition, or via an attachment means thatis part of the integral carrier, e.g. the integral carrier mayoptionally be of sufficient size and/or width and have sufficientadhesiveness, that, once applied, the integral carrier overlaps with theoral soft tissues rendering more of the teeth surface available forbleaching.

Without intending to limit the invention, the strip of materialembodiment is described in more detail below:

FIG. 1 is a perspective view of a substantially flat strip of materialhaving rounded corners;

FIG. 2 is a perspective view of an embodiment of the present invention,disclosing the strip of FIG. 1 upon which a second layer compositioncomprising a composition described herein wherein the bleaching agent isreleaseably associated with the integral carrier and/or the presentcomposition;

FIG. 3 is a cross-sectional view, taken along section line 3-3 of FIG.2, showing an example of the strip of material having a thickness lessthan that of the second layer coated thereon;

FIG. 4 is a cross-sectional view, showing an alternative embodiment ofthe present invention, showing shallow pockets in the strip of material,which act as reservoirs for additional amounts of the second layercoated on the strip;

FIG. 5 is a cross-sectional plan view, showing an alternative embodimentfor applying the second layer composition to adjacent teeth having thestrip of material of the present invention conforming thereto andadhesively attached to the teeth by means of the second layercomposition located between the teeth and the strip of material;

FIG. 6 is a cross-sectional elevation view of a tooth, taken alongsection line 6-6 of FIG. 5, showing the strip of material of the presentinvention conforming to and adhesively attached to the teeth by means ofthe second layer composition located between the teeth and strip ofmaterial;

FIG. 7 is a cross-sectional plan view, similar to FIG. 5, showing astrip of material of the present invention conforming to the teeth andthe adjoining soft tissue and adhesively attached to both sides of theteeth by means of the second layer composition located between the teethand the strip of material;

FIG. 8 is a cross-sectional elevation view, taken along section line 8-8of FIG. 7, showing a strip of material of the present inventionconforming to both the tooth and the adjoining soft tissue andadhesively attached to both sides of the tooth by means of the secondlayer composition located between the teeth and the strip of material;

FIG. 9 is a perspective view of an alternative embodiment of the presentinvention, disclosing the strip of material coated with a second layercomposition of FIG. 2 for treating teeth and adjoining soft tissuehaving a release liner;

FIG. 10 is a cross-sectional view of an alternative embodiment of thepresent invention, taken along section line 10-10 of FIG. 9, showing arelease liner attached to the strip of material by the second layercomposition on the strip of the material.

DETAILED DESCRIPTION

Definitions

By “oral care composition” or “oral composition” as used herein is meanta product which is not intentionally swallowed for purposes of systemicadministration of therapeutic agents, but is retained in the oral cavityfor a sufficient time to contact the dental surfaces for purposes ofwhitening efficacy.

By “safe and effective amount” as used herein is meant an amount of acomponent, high enough to significantly (positively) modify thecondition to be treated or to effect the desired whitening result, butlow enough to avoid serious side effects (at a reasonable benefit/riskratio), within the scope of sound medical/dental judgment. The safe andeffective amount of a component, will vary with the particular condition(e.g., to effect whitening) being treated, the age and physicalcondition of the patient being treated, the severity of the condition,the duration of treatment, the nature of concurrent therapy, thespecific form employed, and the particular vehicle from which thecomponent is applied.

By “a sufficient period of time to achieve whitening” as used hereinmeans that the composition is used or worn by the subject or the subjectis instructed to use or wear the composition for greater than about 2minutes, in another embodiment from about 2.5 minutes to about 12 hours(e.g overnight treatment), in another embodiment from about 3 minutes toabout 120 minutes, in yet another embodiment from about 5 minutes toabout 40 minutes, per application and may be applied from about 1 toabout 7 times per day. Additionally, the length of treatment to achievethe desired benefit, for example, tooth whitening, may last from aboutone day to about six months, in another embodiment from about one day toabout 28 days, and in another embodiment from about 7 to about 28 days.The optimal duration and frequency of application will depend on thedesired effect, the severity of any condition being treated, the healthand age of the user and like considerations.

By “cm” as used herein means centimeter. By “mm” as used herein meansmillimeter.

All percentages and ratios used hereinafter are by weight of totalcomposition, unless otherwise indicated.

All measurements referred to herein are made at 25° C. unless otherwisespecified.

All percentages, ratios, and levels of ingredients referred to hereinare based on the actual amount of the ingredient, and do not includesolvents, fillers, or other materials with which the ingredient may becombined as a commercially available product, unless otherwiseindicated.

All publications, patent applications, and issued patents mentionedherein are hereby incorporated in their entirety by reference. Citationof any reference is not an admission regarding any determination as toits availability as prior art to the claimed invention.

Without being bound by theory, the present invention may increase the“effective” concentration of the bleaching agent on the surface of theteeth due to the replacement of some of the aqueous phase with a waterinsoluble solid phase. In one embodiment this may make the compositionmore hydrophobic. Therefore, increased speed of whitening and/orincreased efficacy of the bleaching agent may be achieved, even thoughthe same or lower total level of the bleaching agent is used. Thepresent invention, therefore, at a given total concentration ofbleaching agent, may require fewer applications to get the same degreeof whitening or may require a lower gel load to get the same degree ofwhitening.

Bleaching Agent

The compositions and methods in the methods of the present inventioncomprise a safe and effective amount of a bleaching agent. Generally thelevel of the bleaching agent is dependent on the available oxygen orchlorine respectively that the molecule is capable of providing tobleach the stain. The bleaching agent is generally used in compositionsof the present invention at levels from about 0.1% to about 20%, inanother embodiment from about 0.5 to about 9% and in another embodimentfrom about 3% to about 8%, and in yet another embodiment from about 4%to about 6%, by weight of the composition, of the bleaching agent. Inone embodiment the bleaching agent is surprisingly more effective whenused at lower levels generally from about 0.5% to about 3%, in anotherembodiment from about 0.5% to about 1.5% by weight of the composition.

Bleaching agents are included in the compositions of the presentinvention. In one embodiment bleaching agents are selected from thegroup consisting of peroxides, metal chlorites, perborates,percarbonates, peroxyacids, persulfates, compounds that form thepreceding compounds in situ, and combinations thereof. Suitable peroxidecompounds include hydrogen peroxide, urea peroxide, calcium peroxide,carbamide peroxide, and mixtures thereof. In one embodiment thebleaching agent is carbamide peroxide. Suitable metal chlorites includecalcium chlorite, barium chlorite, magnesium chlorite, lithium chlorite,sodium chlorite, potassium chlorite, and mixtures thereof. Additionalbleaching agents also include hypochlorite and chlorine dioxide. In oneembodiment the bleaching agent is selected from sodium chlorite,peroxide, sodium percarbonate, oxones, and mixtures thereof. Thestarting bleach agent can be aqueous or solid material.

Water Insoluble Solid Phase

The present invention comprises a safe and effective amount of a waterinsoluble solid phase. Generally the water insoluble solid phasecomprises water insoluble organic and/or inorganic (e.g. particulate)additives. The water insoluble solid phase is generally water insoluble,non-toxic to the user and chemically stable and compatible with thebleaching agent (e.g. not cause substantial decomposition of the bleachagent) and the other ingredients present in the composition. Generally,in one embodiment, the present invention comprises from about 20% toabout 80%, in another embodiment from about 30% to about 75% in anotherembodiment from about 35% to about 65% and in another embodiment fromabout 45% to about 60% by weight of the composition, of the waterinsoluble solid phase.

Suitable materials for the water insoluble solid phase includepolyolefins (e.g., thermoplastic polymers, polymers derived from simpleolefins, polyethylene, polypropylene, polyisoprenes, polybutene, andcopolymers thereof) and polyester, and mixtures thereof. For examplepolyethylene is available under the tradename AC® and Accumist®available from Honeywell Allied Signal. Additional materials for thewater insoluble solid phase include water insoluble celluloses (e.g.ethyl cellulose and cellulose acetate), silicas, talc, mica, magnesiumcarbonate, calcium carbonate, magnesium silicate, aluminum magnesiumsilicate, titanium dioxide, zinc oxide, nylon powder, methacrylatepowder, polystyrene powder, silk powder, crystalline cellulose,titanated mica, calcium phosphate, calcium pyrophosphate, and mixturesthereof. In one embodiment the water insoluble solid phase is selectedfrom the group consisting of polyethylene, polypropylene, polyisoprenes,copolymers thereof, and mixtures thereof.

In one embodiment the water insoluble solid phase comprises less thanabout 5% by weight, in another embodiment less than about 2%, in anotherembodiment is essentially free of, dicalcium phosphate dihydrate,anhydrous dicalcium phosphate, and/or calcium pyrophosphate.

In one embodiment various dyes, colorants, pigments, and mixturesthereof can either be optionally added to the present composition or beoptionally incorporated as part of the water insoluble solid phase, togive the compositions herein colored appearance. Any color, desired bythe consumer, can be used, including dyes or pigments that provide acolor similar to the color of natural teeth. One advantage of coloredcompositions is that it allows the user to see if the composition coverstheir teeth evenly and completely, since the degree of coverage on theteeth is easier to see with a colored composition.

In one embodiment the water insoluble solid phase is a water solublematerial (e.g. water soluble starch material) that is loaded into thecomposition at a high enough level to exceed its solubility in thecomposition and thereafter function as the water insoluble phase.

In one embodiment the average particle size of the water insoluble solidphase, especially if an integral carrier (e.g. strip) is used with thecomposition, is generally less than about 200 microns. In oneembodiment, the average particle size of the water insoluble solid phaseis from about 5 to about 100, in another embodiment from about 5 toabout 80, in yet another embodiment from about 10 to about 60, and inyet another embodiment from about 10 to about 30 microns.

In one embodiment the water insoluble solid phase is compatible with thebleaching agent, which means that the water insoluble solid phase willnot cause significant decomposition of the bleach agent. In anotherembodiment “compatible with the bleaching agent” means that a safe andeffective amount of a stabilizer is added to the water insoluble solidphase or to the composition of this invention. In another embodiment thelevel of optional stabilizer is from about 0.001% to about 15%, and inanother embodiment from about 0.01% to about 10%, in another embodimentfrom about 0.5% to about 5%, in even another embodiment from about 1% toabout 3%, by weight of the composition.

In one embodiment, suitable optional stabilizers, such as chelants ornon-chelant stabilizers as known in the art, may be selected from thegroup consisting of tartaric acid and pharmaceutically acceptable saltsthereof; citric acid and salts thereof such as alkali metal citrates;pyrophosphate ion source; polyphosphates (e.g., tripolyphosphate,hexametaphosphate); diphosphonates (e.g., EHDP; AHP); EDTA; and mixturesthereof; and in another embodiment may be selected from the groupconsisting of sodium citrate, potassium citrate, disodium tartrate,dipotassium tartrate, pyrophosphate ion source, sodium potassiumtartrate, disodium hydrogen tartrate, potassium hydrogen tartrate,disodium dihydrogen pyrophosphate, tetrasodium pyrophosphate,tetrapotassium pyrophosphate, and mixtures thereof.

Water Soluble Liquid Phase

The present invention comprises a safe and effective amount of a watersoluble liquid phase. Generally the level of the water soluble liquidphase is from about 15% to about 80%, in another embodiment from about20% to about 75%, in another embodiment from about 35% to about 70%, inanother embodiment from about 45% to about 65%, by weight of thecomposition. In another embodiment the water soluble liquid phase isfrom about 15% to less than about 50%.

The water soluble liquid phase is generally selected from the groupconsisting of water, polyalkylene glycols with molecular weights fromabout 200 to about 20,000, humectants, and mixtures thereof. The watersoluble liquid phase can comprise water miscible components such aspolyalkylene glycols, humectants, and mixtures thereof. Humectantsgenerally include edible polyhydric alcohols such as glycerin, sorbitol,xylitol, butylene glycol, polyethylene glycol, and propylene glycol, andmixtures thereof. In one embodiment the water soluble liquid phase iswater. In one embodiment the composition comprises at least about 10%water, in another embodiment at least about 20% by weight of thecomposition, of water.

Ratio of Water Insoluble Solid Phase to Water Soluble Liquid Phase

The ratio of the water insoluble solid phase to the water soluble liquidphase is from about 1:4 to about 4:1, in another embodiment is fromabout 1:2.5 to about 2.5:1, in another embodiment from about 1:1.5 toabout 1.5:1, and in yet another embodiment is from about 1:1.25 to about1.25:1.

Whitening Index

In one embodiment, the present invention has a Whitening Index of fromabout 0.5 to about 4, in another embodiment from about 1 to about 4, inyet another embodiment from about 1.3 to about 3.5, and in anotherembodiment from about 1.5 to about 3. The Whitening Index is calculatedas follows:

Db (for composition A) minus Db (for composition B) at treatment day 1,2, 3 or 4 wherein composition A and composition B have the sameconcentration of bleaching agent, by weight of the composition, andcomposition A is a composition of the present invention, having therequisite amount of water insoluble solid phase and water soluble liquidphase at a ratio of from about 1:4 to about 4:1, etc., and composition Bdoes not.

Db for composition A is calculated as follows: 6-8 extracted humanmolars are cleaned and are mounted into Lego® blocks, and the front sideof each molar is labeled to identify each molar. The molars arere-hydrated overnight in either water or phosphate buffer solution.Thereafter, the molars are removed from solution and then 0.03 to 0.1 gof composition A is applied to the front surface of each molar. Themolars are then placed in a 37 degree C. incubator during the durationof the treatment. Each molar is treated with composition A for 30minutes twice daily over a 4-day study period. After 30 minutestreatment time, the molars are removed from the incubator and are rinsedwith distilled water to remove any residual composition. The molars areplaced in the water or buffer solution in between each treatment. Two tofour hours are allowed between each treatment period.

Digital images of the molars are obtained pretreatment (baseline) andafter each total daily treatment (total daily treatment is 1 hour).Digital images of the molars are captured on computer using a highresolution digital camera (HC 1000 CCD®) manufactured by Fuji, Japan.Theses images are analyzed to derive numerical values for average toothcolor in terms of standard CIELAB¹ three dimensional color spacedescribing lightness/brightness from blue to yellow (b). Treatmentefficacy after each day of treatment, b (calculated as the average b foreach molar tested) is compared to the baseline b (calculated as theaverage b for each molar tested) for color measures b denoted as Db. Inone embodiment the baseline b value of the extracted human molars rangesfrom about 10 to about 20, in another embodiment from about 12 to about16.¹ Commission Internationale de l' Eclairage L*a*b* capable ofrepresenting all possible colors using three variables, a luninnce—L*;and color values on a red-green axis—a*; and a blue-yellow axis—b*.

The Whitening Index can be calculated at day 1 or 2 or 3 or 4, or it canan average of the Db from days 1 to 4.

Db for composition B is calculated the same way as for composition Aexcept that composition B is used instead of composition A.

Optional Thickening Agents

The compositions herein optionally comprise a thickening agent. In oneembodiment the thickening agent (or viscosity modifier) functions toincrease retention of the composition on the teeth. The viscositymodifier may further function to inhibit settling and separation ofcomponents or control settling in a manner that facilitatesre-dispersion and may control flow properties of the composition. Aviscosity modifier is particularly useful to keep bleach agents or otheroral care active agents, that are in particulate form, suspended withinthe compositions of the present invention. The thickening agent hereincan also serve as the adhesive means discussed herein below.

When present, the thickening agent (viscosity modifier) is present at alevel of from about 0.01% to about 20%, in one embodiment from about0.1% to about 10%, and in another embodiment from about 0.4% to about5%, and in yet another embodiment from about 1% to about 3%, by weightof the composition.

Suitable viscosity modifiers herein include synthetic polymers such ascellulose derivatives (e.g. methylcellulose, carboxymethylcellulose,hydroxyethylcellulose, hydroxypropylcellulose,hydroxy-propylmethylcellulose, etc.), carbomer polymers (e.g.crosslinked polyacrylic acid copolymer or homopolymer and copolymers ofacrylic acid cross linked with a polyalkenyl polyether), natural andsynthetic gums, karaya gum, guar gum, gelatin, algin, sodium alginate,tragacanth, chitosan, polyethylene oxide, acrylamide polymers,polyacrylic acid, polyvinyl alcohol, polyamines, polyquarternarycompounds, ethylene oxide polymers, polyvinylpyrrolidone, cationicpolyacrylamide polymers, and mixtures thereof.

In one embodiment the thickening agent is selected from carbomers, e.g.the class of homopolymers of acrylic acid crosslinked with an alkylether of pentaerythritol or an alkyl ether of sucrose. Carbomers arecommercially available from B.F. Goodrich as the Carbopol® series. Inone embodiment the carbopols are Carbopol 934, 940, 941, 956, andmixtures thereof. Homopolymers of polyacrylic acid are described, forexample, in U.S. Pat. No. 2,798,053. Other examples of homopolymerswhich are useful include Ultrez 10, ETD 2050, and 974P polymers, whichare available from B.F. Goodrich Company. Such polymers are homopolymersof unsaturated, polymerizable carboxylic monomers such as acrylic acid,methacrylic acid, maleic acid, itaconic acid, maleic anhydride, and thelike.

In another embodiment the thickening agent can be an associativethickener or stabilizer, such as a hydrophobically modified alkalisoluble acrylic emulsion or a hydrophobically modified nonionic polyolpolymer, i.e., a hydrophobically modified urethane polymer,hydrophobically modified ethoxylated urethane polymer or combinationsthereof. Associative thickeners may increase the retention or adhesionof compositions herein and/or integral carriers on the tooth surfaces,may slow the erosion of the compositions once applied on the toothsurfaces, and may improve the release of the compositions from theoptional release liner disclosed herein.

Hydrophobically modified polyacrylic acid polymers are described, forexample, in U.S. Pat. Nos. 3,915,921, 4,421,902, 4,509,949, 4,923,940,4,996,274, 5,004,598, and 5,349,030. These polymers have a largewater-loving hydrophilic portion (the polyacrylic acid portion) and asmaller oil-loving hydrophobic portion (which can be derived from a longcarbon chain acrylate ester). Representative higher alkyl acrylic estersare decycl acrylate, lauryl acrylate, stearyl acrylate, behenyl acrylateand melissyl acrylate, and the corresponding methacrylates. It should beunderstood that more than one carboxylic monomer and more than oneacrylate ester or vinyl ester or ether or styrenic can be used in themonomer charge. The polymers can be dispersed in water and neutralizedwith base to thicken the aqueous composition, form a gel, or emulsify orsuspend a deliverable. Useful polymers are sold as Carbopol® 1342 and1382, and Carbopol® ETD 2020, and Pemulen® TR-1, TR-2, 1621, and 1622,all available from BF Goodrich. The carboxyl containing polymers areprepared from monomers containing at least one activated vinyl group anda carboxyl group, and would include copolymers of polymerizablecarboxylic monomers with acrylate esters, acrylamides, alkylatedacrylamides, olefins, vinyl esters, vinyl ethers, or styrenics. Thecarboxyl containing polymers have molecular weights greater than about500 to as high as several billion, or more, usually greater than about10,000 to 900,000 or more.

Also useful are interpolymers of hydrophobically modified monomers andsteric stabilizing polymeric surface active agents having at least onehydrophilic moiety and at least one hydrophobic moiety or a linear blockor random comb configuration or mixtures thereof. Examples of stericstabilizers which can be used are Hypermerl, which is apoly(12-hydroxystearic acid) polymer, available from Imperial ChemicalIndustries Inc. and Pecosil®, which is a methyl-3-polyethoxypropylsiloxaneΩ.-phosphate polymer, available from Phoenix Chemical,Somerville, N.J. These are taught by U.S. Pat. Nos. 4,203,877 and5,349,030.

Other associative thickeners include Rohm and Haas (such as Acrysol®ICS-1 and Aculyn® 22 and 28 thickeners, which are hydrophobicallymodified alkali-soluble acrylic polymer emulsions and Aculyn® 44 and 46thickener, which is a hydrophobically modified nonionic polyol). In oneembodiment the associative thickener is Carbopol® and/or Pemulen®polymers. The choice of the specific polymer to be employed will dependupon the desired rheology of the composition, and the identity of othercompositional ingredients.

Other associative thickeners are discussed in greater detail in U.S.Pat. No. 5,997,764, BF Goodrich. In one embodiment mixtures ofhydrophobically modified carbomers with carbomers can be used.

Combination of Integral Carrier and Composition

In one embodiment the present invention relates to a delivery systemcomprising an integral carrier and the present composition. In oneembodiment the delivery system comprises: a first layer of a strip ofmaterial; a second layer comprising the above compositions, whereby thebleaching agent is releasably associated with the composition and/or thestrip of material. The present invention delivers whitening benefits tothe oral cavity by directly applying the integral carrier to the teeth.

I. First Layer

The first layer of the present invention comprises an integral carrierincluding a strip of material, dental tray, a sponge material, andmixtures thereof. In one embodiment the integral carrier is a strip ofmaterial.

Referring now to the drawings, and more particularly to FIGS. 1 and 2,there is shown a first embodiment of the present invention, generallyindicated as 10, representing a delivery system for delivering bleachactives to the teeth and the oral cavity. Delivery system 10 has a stripof material 12, which is substantially flat, preferably with roundedcorners.

Releasably applied onto said strip of material 12 is a second layercomposition 14. Second layer composition 14 is, in one embodiment, ahomogenous, and may be uniformly and continuously coated onto strip ofmaterial 12, as shown in FIG. 3. However, second layer composition 14may alternatively be a continuous coating of second layer composition 14along a longitudinal axis of a portion of strip of material 12. Inaddition second layer composition may be laminated or layered whereinthe bleaching agent and/or adhesive means may not be present in alllayers or laminates. In addition second layer composition may be anamorphous mixture of compositions wherein the bleaching agent and/oradhesive means may not be present in all phases of the amorphousmixture. In addition second layer composition may be applied as stripes,spots, and/or other patterns of the same or different compositions,wherein the bleaching agent and/or adhesive means may not be present inall stripes, spots, and/or other patterns of compositions.

As shown in FIG. 4 in an alternative embodiment, strip of material 12may have shallow pockets 18 formed therein. When second layercomposition 14 is coated on a strip of material 12, additional secondlayer composition 14, if present, fills shallow pockets 18 to providereservoirs of second layer composition 14.

FIGS. 5 and 6 show a delivery system 24 of the present invention appliedto the surface of a tooth and plurality of adjacent teeth. Embedded inadjacent soft tissue 20 are a plurality of adjacent teeth 22. Adjacentsoft tissue herein defined as soft tissue surfaces surrounding the toothstructure including: papilla, marginal gingival, gingival sulculus,inter dental gingival, and gingival gum structure on lingual and buccalsurfaces up to and including muco-gingival junction on the pallet.

In both FIGS. 5 and 6, delivery system 24 represents strip of material12 and second layer composition 14, with second layer composition 14 onthe side of strip material 12 facing tooth 22. Second layer composition14 may be pre-applied to strip of material 12, or may be applied tostrip of material 12 by the user prior to application to the teeth. Inan alternate embodiment, the second layer composition may be applieddirectly to teeth 22 by the user and then covered by a strip of material12. In any case, strip of material 12 has a thickness and flexuralstiffness such that it can conform to the contoured surfaces of tooth 22and to adjacent soft tissue 20. In one embodiment, the strip of materialhas sufficient flexibility to form to the contours of the oral surface,the surface being a plurality of adjacent teeth. The strip of materialis also readily conformable to tooth surfaces and to the interstitialtooth spaces without permanent deformation when the delivery system isapplied. The delivery system can be applied without significantpressure.

FIGS. 7 and 8 show a delivery system 24 of the present invention appliedto both front and rear surfaces of a plurality of adjacent teeth 22 aswell as to adjacent soft tissue 20. Delivery system 24 represents stripof material 12 and second layer composition 14, with second layercomposition 14 on the side of strip of material 12 facing tooth 22.

FIGS. 9 and 10 shows an optional release liner 27. Release liner 27 isattached to strip of material 12 by second layer composition 14. Secondlayer composition 14 is on the side of strip material 12 facing releaseliner 27. This side is applied to the tooth and gum surfaces oncerelease liner 27 is removed.

In one embodiment the first layer of the delivery system of the presentinvention is comprised of a strip of material. Such first layermaterials are described in more detail in U.S. Pat. Nos; 6,136,297;6,096,328; 5,894,017; 5,891,453; and 5,879,691, all to Sagel, et al.,and all assigned to The Procter & Gamble Company, and in U.S. Pat. Nos.5,989,569 and 6,045,811 both to Dirksing, et al., and both assigned toThe Procter & Gamble Company.

The strip serves as a protective barrier for the bleach. It preventsleaching and/or erosion of the second layer by for example, the wearer'stongue, lips, and saliva. This allows the active in the second layer toact upon the hard surfaces of the oral cavity for an extended period oftime, from several minutes to several hours.

The strip material may comprise polymers, natural and synthetic wovenmaterials, non-woven material, foil, paper, rubber and combinationsthereof. The strip material may be a single layer of material or alaminate of more than one layer. Regardless of the number of layers, thestrip of material is, in one embodiment, substantially water insoluble.The strip may also be water impermeable. In one embodiment the materialis any type of polymer or combination of polymers that meet the requiredflexural rigidity and are compatible with oral care substances. Suitablepolymers include, but are not limited to, polyethylene,ethylvinylacetate, polyesters, ethylvinyl alcohol and combinationsthereof. Examples of polyesters include Mylar® and fluoroplastics suchas Teflon®, both manufactured by Dupont. In one embodiment the materialis polyethylene. The strip of material is generally less than about 1 mm(millimeter) thick, in one embodiment less than about 0.05 mm thick, inyet another embodiment from about 0.001 to about 0.03 mm thick. Apolyethylene strip of material is generally less than about 0.1 mm thickand in one embodiment from about 0.005 to about 0.02 mm thick.

The shape of the strip of material is any shape and size that covers thedesired oral surface. In one embodiment the strip has rounded corners toavoid irritation of the soft tissue of the oral cavity. “Roundedcorners,” means not having any sharp angles or points. In oneembodiment, the length of the strip material is from about 2 cm(centimeter) to about 12 cm, in another embodiment from about 4 cm toabout 9 cm. The width of the strip material will also depend on the oralsurface area to be covered. The width of the strip is generally fromabout 0.5 cm to about 4 cm, in one embodiment from about 1 cm to about 2cm. In yet another embodiment, the strip may be worn as a patch on oneor several teeth to treat a localized condition.

The strip material may contain shallow pockets. When the composition iscoated on a strip of material, bleach agent and/or oral care activesfill shallow pockets to provide reservoirs of additional bleach agentand/or oral care actives. Additionally the shallow pockets help toprovide texture to the delivery system. In one embodiment the stripmaterial will have an array of shallow pockets. Generally the shallowpockets are approximately 0.4 mm across and about 0.1 mm deep. Whenshallow pockets are included in the strip of material and thecompositions herein are applied to it in various thicknesses, theoverall thickness of the delivery system is less than about 1 mm. In oneembodiment the overall thickness is less than about 0.5 mm.

Flexural stiffness is a material property that is a function of acombination of strip thickness, width and material modulus ofelasticity. This test is a method for measuring the rigidity ofpolyolefin film and sheeting. It determines the resistance to flexure ofa sample by using a strain gauge affixed to the end of a horizontalbeam. The opposite end of the beam presses across a strip of the sampleto force a portion of the strip into a vertical groove in a horizontalplatform upon which the sample rests. A microammeter wired to the straingauge is calibrated in terms of deflection force. The rigidity of thesample is read directly from the microammeter and expressed as grams percentimeter of the sample strip width. In the present invention, thestrip of material has a flexural stiffness of less than about 5 grams/cmas measured on a Handle-O-Meter, model #211-300, available fromThwing-Albert Instrument Company of Philadelphia, Pa. as per test methodASTM D2923-95. In one embodiment the strip has a flexural stiffness lessthan about 3 grams/cm, in another embodiment less than about 2 grams/cmand in yet another embodiment from about 0.1 to about 1 grams/cm.Generally, the flexural stiffness of the strip of material issubstantially constant and does not change during normal use. Forexample, the strip of material does not need to be hydrated for thestrip to achieve the low flexural stiffness in the above-specifiedranges.

This relatively low stiffness enables the strip of material to cover thecontours of the oral surface with very little force being exerted. Thatis, conformity to the contours of the oral surface of the wearer's mouthis maintained because there is little residual force within the strip ofmaterial to cause it to return to its shape just prior to itsapplication to the oral surface, i.e. substantially flat. The strip ofmaterial's flexibility enables it to contact soft tissue over anextended period of time without irritation. The strip of material doesnot require continuous pressure for retention against the oral surface.

In one embodiment the delivery systems herein comprise an adhesion meansand are capable of adhesion to oral surfaces especially the teeth. Thisadhesion means may be provided by the present compositions herein or theadhesion means is provided independently of the compositions herein (forexample the adhesion means is a separate phase from the compositonsherein where the compositions may or may not also have an adhesivemeans). In once embodiment the strip of material is held in place on theoral surface by adhesive attachment provided by the presentcompositions. The viscosity and general tackiness of the presentcompositions to dry surfaces cause the strip to be adhesively attachedto the oral surface without substantial slippage from the frictionalforces created by the lips, teeth, tongue, and other oral surfacesrubbing against the strip of material while talking drinking, etc.However, this adhesion to the oral surface is low enough to allow thestrip of material to be easily removed by the wearer by simply peelingoff the strip of material using one's finger. The delivery system iseasily removable from the oral surfaces without the use of aninstrument, a chemical solvent or agent or excess friction.

In another embodiment the strip of material is held in place on the oralsurface by adhesive means and attachment provided by the integralcarrier itself. In one embodiment the strip of material can extend,attach, and adhere to the oral soft tissue. Alternatively, an adhesivecan be applied to that portion of the strip of material that will attachthe delivery systems to the oral soft tissue. In another embodiment thestrip of material is held in place by an adhesion means that isindependent of the composition of the present inventions herein, asdisclosed in WO 03/015656, published Feb. 27, 2003, SmithKline Beecham.

Examples of adhesion means being provided independent of thecompositions herein include the following.

In one embodiment, the composition and an adhesive material may bedeposited in separate discrete locations in relation to the stripsurface. In one embodiment the composition and adhesive may be depositedon the surface of the strip in respective spatially separated places onthe surface. For example the adhesive may be deposited in places on thestrip surface that enable part of the strip to stick to an oral surfaceadjacent to a tooth surface, e.g. a gum surface, so that another part ofthe strip on which the composition is deposited or into which it isimpregnated may contact the tooth surface.

Alternatively the adhesive and composition may be spatially separatedbut both in locations that enable the adhesive and composition tocontact the same type of tissue, e.g. tooth or gum surface, respectivediscrete spots or patches on the surface, that are relatively small. Forexample parallel lines of the adhesive and composition, one or morepatches of composition bordered partly or completely surrounded by aborder of the adhesive, a single large patch covering substantially theentire surface of the strip and bordered partly or completely by a lineof the adhesive. Adhesive may be deposited on one or more patch borderedpartly or completely surrounded by a border of the composition.

In another embodiment the composition and/or adhesive may beencapsulated. Encapsulation may for example be in micro-capsules, ormacro-capsules. Methods of micro-encapsulation are known, for example inwhich a droplet of a substance in a liquid phase is enclosed within alayer of an encapsulation material, and then separated from the liquid.Such capsules may be deposited on or adjacent the surface of theintegral carrier, and may for example be burst physically or chemically,e.g. by pressure e.g. as the strip is applied to the tooth surface or bysubsequent bit action, by breaching of the capsule wall under the actionof the temperature, moisture, pH, chemicals or enzymes in the mouthenvironment etc. For example respective capsules of composition andadhesive may be attached to the surface of the strip, e.g. by means of asecond adhesive or by embedding the capsules in the strip of material.For example a thin layer of the adhesive may be deposited on the surfaceof the strip, and capsules of the composition may be embedded at leastpartly if not completely within this adhesive layer, or may sit upon thesurface of this adhesive layer.

In another embodiment the adhesive may be provided in granules, e.g.pellets or micropellets, which may release their content under theinfluence of the mouth environment, for example moisture, chemicals orenzymes in the mouth, and may be coated to achieve this release. Methodsof granulation and palletizing are known, as are coating polymers suchas the know Eudragit™ polymers which dissolve at specified pH. Suchadhesive granules may be deposited on or adjacent the surface of thestrip. For example capsules and/or granules of adhesive may be locatedsubstantially uniformly over the strip surface, or alternativelyrespective capsules and/or granules of adhesive may be situated atseparate respective locations on the surface of the strip.

In another embodiment a layer of the composition may be depositedrelatively proximal to, e.g. adjacent to and in contact with thesurface, and a layer of the adhesive may be deposited relatively distalfrom the surface e.g. adjacent to and in contact with the underlyinglayer of composition. In such a construction the adhesive may stick thestrip to the tooth surface, and the composition may pass through theadhesive layer, for example as the adhesive layer becomes permeableunder the influence of the mouth environment. The adhesive layer may insuch a construction have one or more holes passing through the layer tofacilitate the passage of the composition through the adhesive layer.Alternatively for example a layer of the adhesive may be depositedrelatively proximal to, e.g. adjacent to and in contact with thesurface, and a layer of the composition may be deposited relativelydistal from the surface e.g. adjacent to and in contact with anunderlying layer of adhesive. In such a construction the layer ofcomposition may need one or more holes passing through the layer tofacilitate the passage of the adhesive through the composition. In theabove constructions the passage of material from the underlying layermay be facilitated by pressure as the strip is applied to the toothsurface.

Mechanical adhesive means may also be used to provide an adhesivefunction, used either alone or in combination with any other adhesivedevice disclosed herein. In another embodiment mechanical adhesionbetween the strip and tooth or other oral surface is provided by thestrip comprising a plastically deformable material, which can beplastically deformed by the user to conform the strip to the contours ofthe tooth or other oral surface, and so adhere thereto by mechanicalgripping. Such gripping may be enhanced by e.g. surface effects betweenthe strip and the surface such as formation of a partial vacuum orsurface tension effects. For example the strip may have anchors on itssurface, positioned at approximately the spacings of gaps between teeth,and these anchors may fit into the gaps between the teeth. For examplethe surface of the strip which is to contact the tooth surface may beprovided with micro-suckers, that is a plurality of small cavities inthe surface of the strip which can be pressed onto the tooth surface todrive air out therefrom, and thereby create a partial vacuum, so thatthe strip is thereafter held on the tooth surface by air pressure. Suchanchors or micro-suckers may be located on the surface of a strip whichis to contact the tooth surface. Such a strip may for example bestretchable, so that it can be adjusted to the spacings of gaps betweenan individual user's teeth. Another form of “mechanical” adhesion may beprovided by a strip which shrinks in contact with the tooth surface, soit can physically grip the surface of the tooth.

When the adhesive means is provided by an adhesive, the adhesive may beany adhesive which may be used to stick materials to the tooth surfaceor to a surface of the oral cavity surfaces. Suitable adhesives includeskin, gum and muco adhesives, and should be able to withstand themoisture, chemicals and enzymes of the oral environment for long enoughfor the oral care actives and/or bleach to take effect, but may besoluble and/or biodegradable thereafter. Suitable adhesives may forexample comprise water soluble polymers, hydrophobic and/or non-watersoluble polymers, pressure and moisture sensitive adhesives, e.g. dryadhesives which become tacky upon contact with the mouth environment,e.g. under the influence of moisture, chemicals or enzymes etc. in themouth. Suitable adhesives include natural gums, synthetic resins,natural or synthetic rubbers, those gums and polymers listed above under“Thickening Agents”, and various other tacky substances of the kind usedin known adhesive tapes, those known from U.S. Pat. No. 2,835,628.

Second Layer

In one embodiment the second layer comprises a safe and effective amountof the present composition described herein.

Optional Release Liner

The release liner may be formed from any material which exhibits lessaffinity for the second layer composition than the second layercomposition exhibits for itself and for the first layer strip ofmaterial. The release liner may comprise a rigid sheet of material suchas polyethylene, paper, polyester, or other material, which is thencoated with a nonstick type material. The release liner may be cut tosubstantially the same size and shape as the strip of material or therelease liner may be cut larger than the strip of material to provide areadily accessible means for separating the material from the strip. Therelease liner may be formed from a brittle material that cracks when thestrip is flexed or from multiple pieces of material or a scored piece ofmaterial. Alternatively, the release liner may be in two overlappingpieces such as a typical adhesive bandage design. A description ofmaterials suitable as release agents is found in Kirk-Othmer,Encyclopedia of Chemical Technology, Fourth Edition, Volume 21, pp.207-218, incorporated herein by reference.

Combination of Soft/Rigid Dental Trays or Sponge Material (Foams) andComposition

The delivery systems may be used in combination with a dental tray.Dental trays are well known in the whitening art. The general processfor preparing dental trays is known in the art. For example, an alginateimpression which registers all teeth surfaces plus gingival margin ismade and a stone cast is promptly made of the impression. If reservoirsare desired they are prepared by building a layer of rigid material onthe stone cast on specific teeth surfaces to be treated. A dental trayis then vacuum formed from the modified cast using conventionaltechniques. Once formed, the tray is preferably trimmed barely shy ofthe gingival margin on both buccal and lingual surfaces. Enough traymaterial should be left to assure that all of the tooth will be coveredto within about ¼ to about ⅓ mm of the gingival border upon finishingand beveling the tray periphery. In one embodiment one can scallop upand around interdental papilla so that the finished tray does not coverthem. All tray edges are preferably smoothed so that the lip and tonguewill not feel an edge prominence. The resulting tray, in one embodiment,provides a perfect fit of the patient's teeth optionally with reservoirsor spaces located where the rigid material was placed on the stone cast.Dental trays may comprise of soft transparent vinyl material having apreformed thickness from about 0.04 inch to about 0.06 inch. Softmaterial is more comfortable for the patient to wear. Harder material(or thicker plastic) may also be used to construct the tray.

Dentists have traditionally utilized three types of dental appliancesfor bleaching teeth. The first type is a rigid appliance which is fittedprecisely to the patient's dental arches. A second type of rigid customdental appliance is an “oversized” rigid custom dental appliance. Thefabrication of rigid, custom dental appliances entails fabricating stonemodels of the patient's dental arch impressions, and heating andvacuum-forming a thermoplastic sheet to correspond to the stone modelsof a patient's dental arches. Thermoplastic films are sold in rigid orsemi rigid sheets, and are available in various sizes and thickness. Thedental laboratory fabrication technique for the oversized rigid dentalappliance involves augmenting the facial surfaces of the teeth on thestone models with materials such as die spacer or light cured acrylics.Next, thermoplastic sheeting is heated and subsequently vacuum formedaround the augmented stone models of the dental arch. The net effect ofthis method results in an “oversized” rigid custom dental appliance.

A third type of rigid custom dental appliance, used with less frequency,is a rigid bilaminated custom dental appliance fabricated fromlaminations of materials, ranging from soft porous foams to rigid,non-porous films. The non-porous, rigid thermoplastic shells of thesebilaminated dental appliances encase and support an internal layer ofsoft porous foam.

A fourth type of dental tray replaces rigid custom dental applianceswith disposable U-shaped soft foam trays, which may be individuallypackaged, and which may be saturated with a pre-measured quantity of thecomposition of the present invention. The soft foam material isgenerally an open celled plastic material. Such a device is commerciallyavailable from Cadco Dental Products in Oxnard, Calif. under thetradename VitalWhite™. In one embodiment these soft foam trays comprisea backing material (e.g. a closed cell plastic backing material) tominimize the elution of the bleaching agent from the device, into theoral cavity to minimize ingestion by the patient and/or irritation ofthe oral cavity tissues. In another embodiment the soft foam tray isencased by a nonporous flexible polymer. In another embodiment the opencell foam is attached to the frontal inner wall of the dental applianceand/or the open cell foam is attached to the rear inner wall of thedental appliance.

Those of ordinary skill in the art will readily recognize andappreciate, that the present compositions must be thick enough not tosimply run out between the open cell structure of the foam and must bethin enough to slowly pass through the open cell foam over time. Inother words, the open cell foam material has an internal structuralspacing sized relative to the viscosity of the compositions to absorband allow the composition to pass therethrough.

An example of a closed cell material is a closed-celled polyolefin foamsold by the Voltek division of Sekisui America Corporation of Lawrence,Mass. under the tradename Volora which is from {fraction (1/32)}″ to ⅛″in thickness. A closed cell material may also comprise of a flexiblepolymeric material.

An example of an opened cell material is an open celled polyethylenefoam sold by the Sentinel Foam Products division of Packaging IndustriesGroup, Inc. of Hyannis, Mass. under the tradename Opcell which is from{fraction (1/16)}″ to ⅜″ in thickness. Other open cell foam usefulherein include hydrophilic open foam materials such as hydrogel polymers(e.g Medicell™ foam available from Hydromer, Inc. Branchburg, J.J.).Open cell foam may also be hydrophilic open foam material imbibed withagents to impart high absorption of fluids, such as polyurethane orpolyvinylpyrrolidone chemically imbibed with various agents.

Appliances of the above type are further described in U.S. Pat. Nos.5,980,249, M. G. Fontenot, and U.S. Pat. No. 5,575,654, M. G. Fontenot.

The above dental appliances may be designed to be disposable orreuseable. Further dental trays are disclosed in U.S. Pat. No.6,368,576, Steven D. Jensen, issued Apr. 9, 2002; U.S. Pat. No.6,309,625 Jensen, et al., issued Oct. 30, 2001; U.S. Pat. No. 6,183,251,Dan E. Fischer, issued Feb. 6, 2001; U.S. Pat. No. 6,036,943, Dan E.Fischer, issued Mar. 14, 2000; U.S. Pat. No. 5,985,249, Dan E. Fischer,issued Nov. 16, 1999; U.S. Pat. No. 5,846,058, Dan E. Fischer, issuedDec. 8, 1998; U.S. Pat. No. 6,382,979, Sherrill F. Lindquist, issued May7, 2002; U.S. Pat. No. 5,098,303, Fischer, issued Mar. 24, 1992, andU.S. Pat. No. 5,855,870, Dan E. Fischer, issued Jan. 5, 1999.

Optional Oral Care Active Agents

The present invention may optionally comprise a safe and effectiveamount of an oral care active agent selected from the group consistingof anticalculus agent, fluoride ion source, antimicrobial agents,dentinal desensitizing agents, anesthetic agents, antifungal agents,anti-inflammatory agents, selective H-2 antagonists, anticaries agents,nutrients, and mixtures thereof. The oral care active agent preferablycontains an active at a level where upon directed use, the benefitsought by the wearer is promoted without detriment to the oral surfaceto which it is applied. Examples of the oral conditions these activesaddress include, but, are not limited to, appearance and structuralchanges to teeth, whitening, stain bleaching, stain removal, plaqueremoval, tartar removal, cavity prevention and treatment, inflamedand/or bleeding gums, mucosal wounds, lesions, ulcers, aphthous ulcers,cold sores, tooth abscesses, and the elimination of mouth malodorresulting from the conditions above and other causes such as microbialproliferation.

Suitable oral care actives include any material that is generallyconsidered safe for use in the oral cavity and that provides changes tothe overall appearance and/or health of the oral cavity. The level oforal care substance in the compositions of the present invention isgenerally, unless specifically noted, from about 0.01% to about 50%,preferably from about 0.1% to about 20%, more preferably from about 0.5%to about 10%, and even more preferably from about 1% to about 7%, byweight of the composition.

Oral care compositions or substances of the present invention mayinclude many of the actives previously disclosed in the art. Thefollowing is a non-limiting list of oral care actives that may be usedin the present invention.

Anticaries Agents and Fluoride Ion Source

The present composition may comprise a safe and effective amount of ananticaries agent, and mixtures thereof. In one embodiment the anticariesagent is selected from the group consisting of xylitol, fluoride ionsource, and mixtures thereof. The fluoride ion source provides freefluoride ions during the use of the composition. In one embodiment theoral care active agent is a fluoride ion source selected from the groupconsisting of sodium fluoride, stannous fluoride, indium fluoride,organic fluorides such as amine fluorides, and sodiummonofluorophosphate. Sodium fluoride is the fluoride ion in anotherembodiment. Norris et al., U.S. Pat. No. 2,946,725, issued Jul. 26,1960, and Widder et al., U.S. Pat. No. 3,678,154 issued Jul. 18, 1972,disclose such fluoride salts as well as others that can be used as thefluoride ion source. These patents are incorporated herein by referencein their entirety.

Preferably the instant compositions provide from about 50 ppm to 10,000ppm, more preferably from about 100 to 3000 ppm, of fluoride ions in thecompositions that contact dental surfaces when used with the deliverysystem of the present invention.

Anticalculus Agents

The present compositions may comprise a safe and effective amount of atleast one anticalculus agent. This amount is generally from about 0.01%to about 40% by weight of the composition, in another embodiment is fromabout 0.1% to about 25%, and in yet another embodiment is from about4.5% to about 20%, and in yet another embodiment is from about 5% toabout 15%, by weight of the composition. The anticalculus agent shouldalso be essentially compatible with the other components of thecomposition.

The anticalculus agent is selected from the group consisting ofpolyphosphates and salts thereof; polyamino propane sulfonic acid (AMPS)and salts thereof; polyolefin sulfonates and salts thereof; polyvinylphosphates and salts thereof; polyolefin phosphates and salts thereof;diphosphonates and salts thereof; phosphonoalkane carboxylic acid andsalts thereof; polyphosphonates and salts thereof; polyvinylphosphonates and salts thereof; polyolefin phosphonates and saltsthereof; polypeptides; and mixtures thereof. In one embodiment, thesalts are alkali metal salts. In another embodiment the anticalculusagent is selected from the group consisting of polyphosphates and saltsthereof; diphosphonates and salts thereof; and mixtures thereof. Inanother embodiment the anticalculus agent is selected from the groupconsisting of pyrophosphate, polyphosphate, and mixtures thereof.

Polyphosphate

In one embodiment of the present invention, the anticalculus agent is apolyphosphate. A polyphosphate is generally understood to consist of twoor more phosphate molecules arranged primarily in a linearconfiguration, although some cyclic derivatives may be present. Linearpolyphosphates correspond to (X PO₃)_(n) where n is about 2 to about125, wherein preferably n is greater than 4, and X is for examplesodium, potassium, etc. For (X PO₃)_(n) when n is at least 3 thepolyphosphates are glassy in character. Counterions for these phosphatesmay be the alkali metal, alkaline earth metal, ammonium, C₂-C₆alkanolammonium and salt mixtures. Polyphosphates are generally employedas their wholly or partially neutralized water soluble alkali metalsalts such as potassium, sodium, ammonium salts, and mixtures thereof.The inorganic polyphosphate salts include alkali metal (e.g. sodium)tripolyphosphate, tetrapolyphosphate, dialkyl metal (e.g. disodium)diacid, trialkyl metal (e.g. trisodium) monoacid, potassium hydrogenphosphate, sodium hydrogen phosphate, and alkali metal (e.g. sodium)hexametaphosphate, and mixtures thereof. Polyphosphates larger thantetrapolyphosphate usually occur as amorphous glassy materials. In oneembodiment the polyphosphates are those manufactured by FMC Corporationwhich are commercially known as Sodaphos (n≈6), Hexaphos (n≈13), andGlass H (n≈21), and mixtures thereof. The present compositions willtypically comprise from about 0.5% to about 20%, in one embodiment fromabout 4% to about 15%, in yet another embodiment from about 6% to about12%, by weight of the composition of polyphosphate.

The phosphate sources are described in more detail in Kirk & Othmer,Encyclopedia of Chemical Technology, Fourth Edition, Volume 18,Wiley-Interscience Publishers (1996), pages 685-707, incorporated hereinby reference in its entirety, including all references incorporated intoKirk & Othmer.

In one embodiment the polyphosphates are the linear “glassy”polyposphates having the formula:XO(XPO₃)_(n)Xwherein X is sodium or potassium; and n averages from about 6 to about125.

In one embodiment, when n is at least 2 in either of the abovepolyphosphate formulas, the level of anticalculus agent is from about4.5% to about 40%, in another embodiment is from about 5% to about 25%,and in even another embodiment is from about 8% to about 15%, by weightof the composition. Polyphosphates are disclosed in U.S. Pat. No.4,913,895, herein incorporated by reference.

Pyrophosphate

The pyrophosphate salts useful in the present compositions include,alkali metal pyrophosphates, di-, tri-, and mono-potassium or sodiumpyrophosphates, dialkali metal pyrophosphate salts, tetraalkali metalpyrophosphate salts, and mixtures thereof. In one embodiment thepyrophosphate salt is selected from the group consisting of trisodiumpyrophosphate, disodium dihydrogen pyrophosphate (Na₂H₂P₂O₇),dipotassium pyrophosphate, tetrasodium pyrophosphate (Na₄P₂O₇),tetrapotassium pyrophosphate (K₄P₂O₇), and mixtures thereof. Thepyrophosphate salts described in U.S. Pat. No. 4,515,772, issued May 7,1985, and U.S. Pat. No. 4,885,155, issued Dec. 5, 1989, both to Parranet al., are incorporated herein by reference in their entirety, as wellas the references disclosed therein. The pyrophosphate salts aredescribed in more detail in Kirk & Othmer, Encyclopedia of ChemicalTechnology, Third Edition, Volume 17, Wiley-Interscience Publishers(1982), pages 685-707, incorporated herein by reference in its entirety,including all references incorporated into Kirk & Othmer.

In one embodiment, the compositions of the present invention comprisetetrasodium pyrophosphate. Tetrasodium pyrophosphate may be theanhydrous salt form or the decahydrate form, or any other species stablein solid form in the present compositions. The salt is in its solidparticle form, which may be its crystalline and/or amorphous state, withthe particle size of the salt preferably being small enough to beaesthetically acceptable and readily soluble during use.

The level of pyrophosphate salt in the compositions of the presentinvention is any safe and effective amount, and is generally from about1.5% to about 15%, in another embodiment from about 2% to about 10%, andyet in another embodiment from about 3% to about 8%, by weight of thecomposition.

Other Anticalculus Agents

Polyolefin sulfonates include those wherein the olefin group contains 2or more carbon atoms, and salts thereof. Polyolefin phosphonates includethose wherein the olefin group contains 2 or more carbon atoms.Polyvinylphosphonates include polyvinylphosphonic acid. Diphosphonatesand salts thereof include azocycloalkane-2,2-diphosphonic acids andsalts thereof, ions of azocycloalkane-2,2-diphosphonic acids and saltsthereof (such as those which the alkane moiety has five, six or sevencarbon atoms, in which the nitrogen atom is unsubstituted or carries alower alkyl substitutent, e.g. methyl), azacyclohexane-2,2-diphosphonicacid, azacyclopentane-2,2-diphosphonic acid,N-methyl-azacyclopentane-2,3-diphosphonic acid, EHDP(ethanehydroxy-1,1,-diphosphonic acid), AHP(azacycloheptane-2,2-diphosphonic acid, a.k.a.1-azocycloheptylidene-2,2-diphosphonic acid),ethane-1-amino-1,1-diphosphonate, dichloromethane-diphosphonate, etc.Phosphonoalkane carboxylic acid or their alkali metal salts include PPTA(phosphonopropane tricarboxylic acid), PBTA(phosphonobutane-1,2,4-tricarboxylic acid), each as acid or alkali metalsalts. Polyolefin phosphates include those wherein the olefin groupcontains 2 or more carbon atoms. Polypeptides include polyaspartic andpolyglutamic acids.

Azacycloalkane-2,2-diphosphonic acids are disclosed in U.S. Pat. No.3,941,772, issued Mar. 2, 1976, Ploger et al., assigned to Henkel andU.S. Pat. No. 3,988,443, issued Oct. 26, 1976, Ploger et al., which areherein incorporated by reference in their entirety.

Optional agents to be used in place of or in combination with thepyrophosphate salt include such known materials as synthetic anionicpolymers, including polyacrylates and copolymers of maleic anhydride oracid and methyl vinyl ether (e.g., Gantrez), as described, for example,in U.S. Pat. No. 4,627,977, to Gaffar et al., the disclosure of which isincorporated herein by reference in its entirety; as well as, e.g.,polyamino propoane sulfonic acid (AMPS), zinc citrate trihydrate,polyphosphates (e.g., tripolyphosphate; hexametaphosphate),diphosphonates (e.g., EHDP; AHP), polypeptides (such as polyaspartic andpolyglutamic acids), and mixtures thereof.

Antimicrobial Agents

Antimicrobial antiplaque agents may also by optionally present in thepresent compositions. Such agents may include, but are not limited to,triclosan, 5-chloro-2-(2,4-dichlorophenoxy)-phenol, as described in TheMerck Index, 11th ed. (1989), pp. 1529 (entry no. 9573) in U.S. Pat. No.3,506,720, and in European Patent Application No. 0,251,591 of BeechamGroup, PLC, published Jan. 7, 1988; chlorhexidine (Merck Index, no.2090), alexidine (Merck Index, no. 222; hexetidine (Merck Index, no.4624); sanguinarine (Merck Index, no. 8320); benzalkonium chloride(Merck Index, no. 1066); salicylanilide (Merck Index, no. 8299);domiphen bromide (Merck Index, no. 3411); cetylpyridinium chloride (CPC)(Merck Index, no. 2024; tetradecylpyridinium chloride (TPC);N-tetradecyl-4-ethylpyridinium chloride (TDEPC); octenidine; delmopinol,octapinol, and other piperidino derivatives; effective antimicrobialamounts of essential oils and combinations thereof for example citral,geranial, and combinations of menthol, eucalyptol, thymol and methylsalicylate; antimicrobial metals and salts thereof for example thoseproviding zinc ions, stannous ions, copper ions, and/or mixturesthereof; bisbiguanides, or phenolics; antibiotics such as augmentin,amoxicillin, tetracycline, doxycycline, minocycline, and metronidazole;and analogs and salts of the above antimicrobial antiplaque agents;anti-fungals such as those for the treatment of candida albicans. Ifpresent, these agents generally are present in a safe and effectiveamount for example from about 0.1% to about 5% by weight of thecompositions of the present invention.

Antiinflammatory Agents

Anti-inflammatory agents may also be present in the oral compositions ofthe present invention. Such agents may include, but are not limited to,non-steroidal anti-inflammatory agents such as aspirin, ketorolac,flurbiprofen, ibuprofen, naproxen, indomethacin, aspirin, ketoprofen,piroxicam and meclofenamic acid, COX-2 inhibitors such as valdecoxib,celecoxib and rofecoxib, and mixtures thereof. If present, theanti-inflammatory agents generally comprise from about 0.001% to about5% by weight of the compositions of the present invention. Ketorolac isdescribed in U.S. Pat. No. 5,626,838, issued May 6, 1997, incorporatedherein by reference in its entirety.

H-2 Antagonists

The present invention may also include a safe and effective amount of aselective H-2 antagonist. Selective H-2 antagonists include compoundswhich are disclosed in U.S. Pat. Nos. 5,294,433 and 5,364,616 Singer etal., issued Mar. 15, 1994 and Nov. 15, 1994 respectively and assigned toProcter & Gamble, wherein the selective H-2 antagonist is selected fromthe group consisting of cimetidine, etintidine, ranitidine, ICIA-5165,tiotidine, ORF-17578, lupitidine, donetidine, famotidine, roxatidine,pifatidine, lamtidine, BL-6548, BMY-25271, zaltidine, nizatidine,mifentidine, BMY-25368 (SKF-94482), BL-6341A, ICI-162846, ramixotidine,Wy-45727, SR-58042, BMY-25405, loxtidine, DA-4634, bisfentidine,sufotidine, ebrotidine, HE-30-256, D-16637, FRG-8813, FRG-8701,impromidine, L-643728, and HB-408. Particularly preferred is cimetidine(SKF-92334),N-cyano-N′-methyl-N″-(2-(((5-methyl-1H-imidazol-4-yl)methyl)thio)ethyl)guanidine:

Cimetidine is also disclosed in the Merck Index, 11th edition (1989), p.354 (entry no. 2279), and Physicians' Desk Reference, 46th edition(1992), p. 2228. Related preferred H-2 antagonists include burimamideand metiamide.

Nutrients

Nutrients may improve the condition of the oral cavity and can beincluded in the oral care compositions or substances of the presentinvention. Nutrients include minerals, vitamins, oral nutritionalsupplements, enteral nutritional supplements, and mixtures thereof.

Minerals that can be included with the compositions of the presentinvention include calcium, phosphorus, fluoride, zinc, manganese,potassium and mixtures thereof. These minerals are disclosed in DrugFacts and Comparisons (loose leaf drug information service), WoltersKluer Company, St. Louis, Mo., ©1997, pp 10-17.

Vitamins can be included with minerals or used separately. Vitaminsinclude Vitamins C and D, thiamine, riboflavin, calcium pantothenate,niacin, folic acid, nicotinamide, pyridoxine, cyanocobalamin,para-aminobenzoic acid, bioflavonoids, and mixtures thereof. Suchvitamins are disclosed in Drug Facts and Comparisons (loose leaf druginformation service), Wolters Kluer Company, St. Louis, Mo., ©1997, pp.3-10.

Oral nutritional supplements include amino acids, lipotropics, fish oil,and mixtures thereof, as disclosed in Drug Facts and Comparisons (looseleaf drug information service), Wolters Kluer Company, St. Louis, Mo.,©1997, pp. 54-54e. Amino acids include, but, are not limited toL-Tryptophan, L-Lysine, Methionine, Threonine, Levocarnitine orL-carnitine and mixtures thereof. Lipotropics include, but, are notlimited to choline, inositol, betaine, linoleic acid, linolenic acid,and mixtures thereof. Fish oil contains large amounts of Omega-3 (N-3)Polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoicacid.

Antioxidants that may be included in the oral care composition orsubstance of the present invention include, but are not limited toVitamin E, ascorbic acid, Uric acid, carotenoids, Vitamin A, flavonoidsand polyphenols, herbal antioxidants, melatonin, aminoindoles, lipoicacids and mixtures thereof.

Enteral nutritional supplements include, but, are not limited to proteinproducts, glucose polymers, corn oil, safflower oil, medium chaintriglycerides as disclosed in Drug Facts and Comparisons (loose leafdrug information service), Wolters Kluer Company, St. Louis, Mo., ©1997,pp. 55-57.

Desensitizing Agents

Anti-pain or desensitizing agents can also be present in the oral carecompositions or substances of the present invention. Such agents mayinclude, but are not limited to, strontium chloride, potassium nitrate,natural herbs such as gall nut, Asarum, Cubebin, Galanga, scutellaria,Liangmianzhen, Baizhi, etc.

Optional Colorants

Dyes, pigments, colorants, and mixtures thereof may optionally beincluded in the compositions of the present invention to give thecompositions herein colored appearance. An advantage of adding pigmentsand/or colorants to the compositions herein is that it will allow theuser to see if the composition covers their teeth evenly and completely,since coverage is easier to see with a colored composition. In oneembodiment the colorant provides color similar to the color of naturalteeth. Colorants useful herein are stable with the bleach agent and arethose recognized as safe.

The levels of dye, pigments and colorants that are optionally usedherein are in the range of about 0.05% to about 20%, in anotherembodiment from about 0.10% to about 15% and in another embodiment fromabout 0.25% to about 5% by weight of the composition.

Methods of Manufacturing the Compositions

The integral carrier, such as a strip, may be formed by several of thefilm making processes known in the art. In one embodiment a strip ofpolyethylene is made by a blown process or a cast process. Otherprocesses including extrusion or processes that do not affect theflexural rigidity of the strip of material are also feasible.Additionally, the second layer composition may be incorporated onto thestrip during the processing of the strip. The second layer compositionmay be a laminate on the strip.

Methods of Using the Compositions

The present invention can be applied to the teeth of a consumer in thedental office by a dental professional, or can be used at home by theconsumer.

In practicing the present invention, the user applies the composition ordelivery system herein to one or more teeth. The composition can beapplied with a paint-on device, a syringe or unit dose syringe,squeezable tube, a brush, a pen or brush tip applicator, a doe's footapplicator, or the like, or even with the finger(s). The composition canalso be combined with an integral carrier such as a strip of material,dental tray, and/or sponge material, and thereafter applied to theteeth. In one embodiment, the delivery systems herein are almostunnoticeable when applied to the teeth.

Then, any residual composition may be easily removed by wiping, brushingor rinsing the oral surface after a desired period of time has elapsed,or in the normal course of tooth brushing or other oral care activities.

It is not necessary to prepare the teeth before applying the compositionor delivery systems of the present invention. For example, the user mayor may not choose to brush the teeth or rinse the mouth before applyingthe present invention. The surfaces of the oral cavity are neitherrequired to be dried nor to be excessively wet with saliva or waterbefore application. However, it is believed that adhesion to the toothenamel surfaces will be improved if the teeth are dry prior toapplication.

Where the integral carrier is a strip of material, the second layercomposition may be coated on the strip of material, or be applied by theuser to the strip of material, or be applied by the user to the teethand then the strip of material placed over the coated teeth. The amountof the second layer composition applied to the strip of material orteeth may depend upon the size and capacity of the strip of material,concentration of the bleach agent and the desired benefit. Generallyless than 1 gram of composition is required, in one embodiment fromabout 0.001 grams to about 0.0001 grams and in another embodiment fromabout 0.1 gram to about 0.4 grams of composition is used. The amount ofcomposition per square centimeter (cm) of material is less than about 1gram/cm², in another embodiment less than about 0.2 grams/cm², inanother embodiment about 0.0001 grams/cm² to about 0.1 grams/cm², and inyet another embodiment about 0.01 grams/cm² to about 0.04 grams/cm².

The composition of the present invention may be in the form of a viscousliquid, paste, gel, solution or other suitable form. In one embodimentthe composition has a viscosity of from about 200 to about 1,000,000 cpsat low shear rates (less than one 1/seconds). In another embodiment theviscosity is from about 100,000 to about 800,000 cps and in anotherembodiment from about 400,000 to about 600,000 cps.

In one embodiment the composition is a non-dentifrice, non-foaming,whitening composition, e.g. a whitening gel, wherein the whiteningcomposition can for example, either be essentially free of foamingsurfactants and, or essentially free of a fluoride ion source.

The present invention may allow for a decreased frequency ofapplication. For example, a 6% peroxide containing composition thatgenerally is used for 30 minutes twice daily for 2 weeks (e.g. for atotal application time of 14 hours), may show substantially identicalwhitening efficacy by administering the same level of peroxide but usedin accordance with the present invention, wherein the total applicationtime is reduce to 6-10 hours. For example, when used in accord with thepresent invention the same level of bleach agent may achieve equal orsimilar efficacy with one 30 minute application per day for 14 days or a30 minute application twice daily for 7-10 days.

Dental tray appliances may be used as follows. The patient or dentalprofessional dispenses the present composition into a soft or rigiddental appliance and then the subject places the appliance over thesubject's dental arch (or fits the device around his or her teeth tokeep the tray in position). Generally, the recommended treatment periodis the same as those discussed above. At the end of the treatmentperiod, the dental appliance is removed, cleaned with water to removeany remaining composition, and then stored until the next application.

The above-described compositions and delivery systems may be combined ina kit which comprises: 1. composition and 2. instructions for use; orcomprises: 1. composition, 2. instructions for use, and 3. an integralcarrier.

The compositions of this invention are useful for both human and otheranimals (e.g. pets, zoo, or domestic animals) applications.

EXAMPLES

The following non-limiting examples further describe preferredembodiments within the scope of the present invention. Many variationsof these examples are possible without departing from the scope of theinvention.

EXAMPLE I

The following compositions containing a bleaching agent, are made byprocessing techniques described below: Example 1 Example 2 Example 3Ingredient Wt % Wt % Wt % Glycerin 10.0 10.0 10.0 Water 20.3 17.3 21.5Carbopol 956² 2.0 5.0 0.8 Sodium Acid 0.4 0.4 0.4 Pyrophosphate SodiumStannate 0.2 0.2 0.2 Sodium Saccharin 0.1 0.1 0.1 Polyethylene 50.0 50.050.0 Hydrogen Peroxide (35% 17.0 17.0 17.0 active) Example 4 Example 5Example 6 Ingredient Wt % Wt % Wt % Glycerin 10.0 10.0 10.0 Water 28.53.3 45.3 Carbopol ETD 2020³ 2.3 Sodium Acid 0.4 0.4 0.4 PyrophosphateSodium Stannate 0.2 0.2 0.2 Sodium Saccharin 0.1 0.1 0.1 Polyethylene50.0 50.0 25.0 Hydrogen Peroxide (35% 8.5 34.0 17.0 active) Carbopol1342⁴ 2.0 Carbopol 1382⁵ 2.0 Example 7 Example 8 Ingredient Wt % Wt %Glycerin 10.0 10.0 Water 20.3 20.3 Pemulen TR 1⁶ 2.0 Sodium Acidpyrophosphate 0.4 0.4 Sodium Stannate 0.2 0.2 Sodium Saccharin 0.1 0.1Polypropylene 50.0 50.0 Hydrogen Peroxide (35% 17.0 17.0 active) PemulenTR2⁷ 2.0²Available from BF Goodrich.³Available from BF Goodrich.⁴Available from BF Goodrich.⁵Available from BF Goodrich.⁶Available from BF Goodrich.⁷Available from BF Goodrich.

Examples 1-8 are made via the following process. Carbopol or Pemulen,glycerin, water, pyrophosphate, saccharin, stannate and hydrogenperoxide are mixed together at room temperature for 15-20 minutes @ 150rpms. The pH of the resulting mixture is then adjusted to about 4.5-5.0by adding a 50/50 sodium hydroxide solution. Half of the desired amountof polyethylene is then mixed with the above mixture for about 10minutes at room temperature @ 150 rpms. The remaining half of thepolyethylene is then added and mixed for another 10 minutes at roomtemperature @ 150 rpms to provide the final gel formulation.

About 0.1-0.2 g of the above composition may be applied directly to theteeth by any application methods disclosed herein. Alternatively theabove compositions may be combined with an integral carrier such as astrip of material or tray and then applied to the teeth. About 0.1-0.2 gor about 1-3 g of the above composition may be combined with a strip ofmaterial or tray, respectively. One example of a strip of material is a0.013 mm thick piece of polyethylene film. The strip of material may beprovided with an array of shallow pockets, typically 0.4 mm across and0.1 mm deep. The strip of material has a flexural stiffness of about 0.6grams/centimeter as measured on a Handle-O-Meter, model #211-300,available from Thwing-Albert Instrument Co. of Philadelphia, Pa., as pertest method ASTM D2923-95.

Any of the compositions described above can be used with any of theintegral carriers described herein, e.g. strip of material, trays,and/or foam materials. In any of the above examples the polyethylene canbe white or the color of natural teeth, allowing the user to apply amore even and continuous coating on the teeth. The above examples have aWhitening Index of from about 0.5 to about 4.

All documents cited in the Detailed Description of the Invention are, inrelevant part, incorporated herein by reference; the citation of anydocument is not to be construed as an admission that it is prior artwith respect to the present invention.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. A oral care delivery system comprising: a. an integral carrier; andb. a safe and effective amount of a composition comprising:
 1. a safeand effective amount of a bleaching agent;
 2. a safe and effectiveamount of a water insoluble solid phase; and
 3. a safe and effectiveamount of a water soluble liquid phase; wherein the ratio of the waterinsoluble solid phase to the water soluble liquid phase is from about1:4 to about 4:1; wherein the composition is applied for a sufficientperiod of time to achieve whitening; and wherein the delivery system iscapable of adhesion to hard or soft tissue of the oral cavity.
 2. Thedelivery system of claim 1 wherein the composition has from about 20% toabout 80% by weight of the water soluble liquid phase.
 3. The deliverysystem of claim 2 wherein the ratio is from about 1:1.5 to about 1.5:1.4. The delivery system of claim 3 wherein the ratio is from about 1:1.25to about 1.25:1.
 5. The delivery system of claim 2 wherein thecomposition comprises from about 45% to about 65% by weight watersoluble liquid phase.
 6. The composition of claim 5 wherein thecomposition comprises from about 45% to about 60% by weight of the waterinsoluble solid phase.
 7. The delivery system of claim 2 wherein thewater insoluble solid phase is selected from the group consisting ofpolyolefins, polyethylene, polypropylene, polyisoprenes, polyester,silicas, talc, mica, magnesium carbonate, calcium carbonate, magnesiumsilicate, aluminum magnesium silicate, titanium dioxide, zinc oxide,nylon powder, methacrylate powder, polystyrene powder, silk powder,crystalline cellulose, titanated mica, calcium phosphate, calciumpyrophosphate, and mixtures thereof.
 8. The delivery system of claim 7wherein the water insoluble solid phase is polyethylene.
 9. The deliverysystem of claim 2 wherein the water insoluble solid phase is selectedfrom the group consisting of organic additives and mixtures thereof. 10.The delivery system of claim 1 wherein the composition comprises fromabout 0.1% to about 20% by weight bleaching agent wherein the bleachingagent is selected from the group consisting of peroxides, metalchlorites, perborates, percarbonates, peroxyacids, persulfates, andcombinations thereof.
 11. The delivery system of claim 1 furthercomprising a Whitening Index of from about 0.5 to about
 4. 12. Thedelivery system of claim 11 wherein the Whitening Index is from about1.3 to about 3.5.
 13. The delivery system of claim 1 wherein theintegral carrier is a strip of material.
 14. The delivery system ofclaim 13 wherein the strip of material and the composition appliedthereon have an overall thickness of less than about 1 mm.
 15. Thedelivery system of claim 13 wherein the strip of material has shallowpockets on a composition-coated side of the strip of material, theshallow pockets having at least some of the composition located therein.16. The delivery system of claim 13 wherein the strip of material is apolyethylene film having a film thickness of less than about 0.1 mm. 17.The delivery system of claim 13 wherein the composition is applied as asubstantially uniform continuous coating on the strip of material. 18.The delivery system of claim 13 wherein the strip of material is held inplace by an adhesion means that is independent of the composition. 19.The delivery system of claim 17 wherein the amount of composition persquare centimeter (cm) of material is less than about 1 gram/cm². 20.The delivery system of claim 1 wherein the integral carrier is a tray.21. The delivery system of claim 1 wherein the integral carrier is asponge material.
 22. The delivery system of claim 1 wherein thecomposition further comprises a dye, colorant, pigment, and mixturesthereof.
 23. The delivery system of claim 1 wherein the compositionfurther comprises an associative thickener.
 24. The delivery system ofclaim 23 wherein the associative thickener is an acrylate/C10-C30 alkylacrylate crosspolymer.
 25. A method of increasing the efficacy of ableaching agent in an aqueous oral care composition comprising: 1.combining an oral care delivery system comprising: a. an integralcarrier; and b. a safe and effective amount of a compositioncomprising:
 1. a safe and effective amount of a bleaching agent;
 2. asafe and effective amount of a water insoluble solid phase; and
 3. asafe and effective amount of a water soluble liquid phase;  wherein theratio of the water insoluble solid phase to the water soluble liquidphase from about 1:4 to about 4:1; and
 2. thereafter applying a safe andeffective amount of the composition to a plurality of teeth of a subjectin need thereof for a sufficient period of time to achieve whitening.